test(federation): require all Step-CA env vars for stepCaRun gate

Guard against partial env var sets where STEP_CA_AVAILABLE=1 is set
but provisioner key or root cert path are missing, which would cause
CaService constructor to throw during NestJS module instantiation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/gateway/src/__tests__/integration/federation-m2-e2e.integration.test.ts

@@ -54,7 +54,12 @@ import { GrantsService } from '../../federation/grants.service.js';
 import { EnrollmentService } from '../../federation/enrollment.service.js';
 
 const run = process.env['FEDERATED_INTEGRATION'] === '1';
-const stepCaRun = run && process.env['STEP_CA_AVAILABLE'] === '1';
+const stepCaRun =
+  run &&
+  process.env['STEP_CA_AVAILABLE'] === '1' &&
+  !!process.env['STEP_CA_URL'] &&
+  !!process.env['STEP_CA_PROVISIONER_KEY_JSON'] &&
+  !!process.env['STEP_CA_ROOT_CERT_PATH'];
 
 const PG_URL = 'postgresql://mosaic:mosaic@localhost:5433/mosaic';